Tire pressure gauge



Nov. l8, 1927. I

Patented Nov. 8, i927,

` maar naar; n. nfs-Laon, or' cti-fences FALLS, onro, Assrelvonjro :ariane-AGE vALvn loon.-A

ronnfrrolv, or CHARLES-ron, wnsr vrncfrninv, n conronerron orwns'r vrne'na. f

TIRE Pansen-nn entren.

Application filed anuaxiyA 17, i923. 4Serial No. 613,256. Y

Pressure gauges have heretofore been made which have been provided with a moving plunger in the tire stem, the vmovement of the plunger indicating the pressure to which the tire was subjected7 the plunger carrying, the valve and serving as a means of iniiation. From necessity the plunger' must be connected with the tire so as to be subjected to the tire pressure' and where the inflation is through the plunger the4 connection must be such as to complete the inflation conduit leading to the tire. A common means of accomplishingthis `has been to secure a rubbertube to the plunger and to the inner end of the stemfthe rubber tube maintaining the connection as the plunger moves through the stretching of the tube. been experienced. in getting rubber of sufficient strength. and elasticity to Asustain, vthe strain of continued use without developing leaks and vobviously theleast escape of air prohibitive.

With the present invention the strain on the Vtube is largely eliminated and this is accomplished by folding the tube upon itself and instead of stretching the tube as vfoi'- merly the movement Vof the plungerl is accommo-dated by the rolling of the fold. The invention further consists in a convenient means of applying a spring to a guage of this type and to other details of construction which will appear from. the specication and claims. v

The invention is illustrated in the accompanying drawing in which a central vertical section of the stem is shown.

l marks the tire stem, 2 the head on the stem, 3 a tire tube, 4 a clamping plate for engaging the tube at the stem, 5 the usual spreader, and 6 a clamping nut for exerting pressure on the clamping plate and securing thespreader.

A plunger 7 is slidingly mounted in the stem. This has an inliation opening 8 through it which is controlled by an inflation valve 9. A key-word l is arranged in thev plunger and this engages a key 11 on a thimble 12 and locks the plunger against turning as it is subjected to the st-rain incident to attaching an inflating device. The outer end of the plunger is screw-threaded for convenience of attaching an inflating device and the usual cap 11i is provided for the end of the plunger. A transparent cap l ismounted on the stem through which Great diculty has` the position of the plunger may be observed to ascertain the pressure to which thetire'is subjected. f i in extension 16 is secured to the' plunger;A the plunger being screw-threaded at 17 at its lower end and this extension screwed into the screw-threaded portion. The extension is provided with a. shoulder 18 at Vits lower' end and` la spring 19 is seated on this shoulder'. The upper end of the springengages arrinf` turned shoulder 2O on'ananchorpiece 21. The anchor piece extends upffromth'e' head? to an intermediate position in the stem and is provided with an out-turned flange 2'2` at its lower end. This flange is clamped the bottom of a screw-threaded socketQB by the end of the stem 1 as it sscrewedinto' the( socket in the head. p i Y' The upper end of the anchor piecehasan opening 2e through which the extension passes. This same opening forms a` means of communication through the perforation y 24a in the head and anchor piece 2l which is anchor piece' being provided with grooves i so as to more readily secure the tube". AL' band 27 1s `arrange d over the tube', thjus clamping the' tube on the anchor piece and the tube is folded Within (itself at 28, the inner port-ion of the tube extending" down along the' 'extension 16. The extension has' the grooves 29 arranged in it and the end of the tubeis clamped against these grooves so as to form a seal by a vband 30. The end of the plunger has a curved face 7a to follow the contour of the fold 28.'

The operation of the device is as follows: The pressure of the tire isfcommunicated through the opening 24a, anchor piece '21, to the tube and this tube, it will be noted, is entirely sealed Vso that the air under pressure follows up between the outer and inner wall of the tube and the plunger issubjected to the vair pressure of the tire and moves outwardly against the resistance of the spring to a point where the spring balances the pressure. rlhe spring is calibrated so that the position ofthe plunger will indicate Vthe pressure in the tire. It will be noted that as the plungermoves outwardly the fold of the tube varies to accommodate the movement so that the tube itself is subjected to no additional stretching action by Ill) ,reason of the movement of the plunger. `Nonelastic material may be, therefore,used

if desired although the material should be flexible in order to make the fold. In this way the ltube is relieved of excessive strain and its life thus very much extended.

What I claim as new is 1. In a tire pressure gauge, the combination of a stem; a plunger in the stem indiinflation connection; a flexible tube formingV an extensible connection between the plunger and the stem, said tube being folded upon itself, the fold varying to accommodate the movement of the plunger, the inner portion ofthe tube extending along the extension; and'a'spring arranged around the extension, said spring being more remote from the plunger than the flexible tube and acting on the extension to resist the movement of the plunger. 4

2.V In a tire pressure gauge, the combination ofV a stem; a plunger'in the stem indicating by its movement the tire pressure, said plunger having an extension, said plunger and extension forming a part of the inflation connection; a flexible tube forming an extensible connection between the plunger and the stem, said tube being folded upon itself,`the.fold varying to accommodate the movement of the plunger, the inner portion of 'the tube extending along the extension; a spring acting on the extension for resisting the movement of the plunger, said spring beingmore remote from the plunger than the folded tube; and an anchor piece for the spring and tube arranged intermediate the,

ends of the stem. Y

3. In atire pressure gauge, the combination of a stem; a plunger in the stem indicating byV its movement the tire pressure, Y

said plunger havingl an extension, said Yplunger and extension forming a part of the inflation connection; a flexible tube formingv an extensible connection between the plunger and the stem, said tube being Vfolded upon itself, the fold varying to accommodate the movement of the plunger, the inner portion of the tube extending along the extension;-

stem, said tube being foldedupon itself, Vthe fold varying to accommodate the movement of the plunger; an extension on the plunger along which the inner portion of the tube extends and to which ther inner end of the tube is secured; an anchor piece extending upwardly from the head to an intermediate portion in the stem to which the outer end of the tube is secured, said anchor piece Y forming a means of connectionthrough the head to the tire; and a spring arranged within the anchor piece and seated against the anchor piece atv its upper end and against the extension atits lower end, said spring resisting the movement of the plunger, said spring being more remote from the plunger than the folded tube. Y

In testimony whereof I have hereunto set my hand.

PARK E. VVELTON.V 

